Chapter 153 opens with a description of the "rare stone" of "an extraordinary origin" . The reader is told that the stone is called the "genuine magnetic stone" because it has the ability to change color. It is also called a "wolf-killer" because of its ability to kill thousands of shadow kings. The narrator explains that the test to pass the stone requires the applicant to change the stone's color. He says that two cultivators in the enlightened realm have failed before him, and that the "ao xiang" killed 3000 shadow kings by himself on a hulun-grassland. He concludes that the applicants must have been at least the "top celestial realm." The narrator points out that this stone seems to have a special power because it contains the power of the rules of "the seven elements" , which are metal , wood , water , fire , earth , wind , and thunder . He explains that it is very difficult to combine these rules, but now that he can act rashly, he can do so. The thunder rules alone is even worse than the thunder rules of hua-tianming .